Continental Student Roster Pivot

Hard

You are given a Student table with the following columns: name: student name continent: one of America, Asia, Europe A reporting team needs a side-by-side roster where each continent becomes its own output column. Build a pivoted report with columns: America Asia Europe Rules: For each continent, sort names alphabetically. Place the first name from each continent on row 1, second name on row 2, and so on. If a continent has no name for a row index, return NULL for that cell. Return columns in the exact order America, Asia, Europe. Data guarantee for this version: The number of students from America is greater than or equal to the number from Asia and Europe. Supported submissions: SQL (SQLite 3.27.2) Pandas (Python)

Example 1

Input

Student:
| name   | continent |
|--------|-----------|
| Jane   | America   |
| Pascal | Europe    |
| Xi     | Asia      |
| Jack   | America   |

Output

[
  {"America":"Jack","Asia":"Xi","Europe":"Pascal"},
  {"America":"Jane","Asia":null,"Europe":null}
]

Explanation

Each continent is sorted independently. America contributes Jack then Jane, while Asia and Europe only contribute one value each, so row 2 gets null padding.

Example 2

Input

Student:
| name    | continent |
|---------|-----------|
| Bruno   | Europe    |
| Aiko    | Asia      |
| Aria    | America   |
| Mateo   | America   |
| Zane    | America   |
| Hana    | Asia      |

Output

[
  {"America":"Aria","Asia":"Aiko","Europe":"Bruno"},
  {"America":"Mateo","Asia":"Hana","Europe":null},
  {"America":"Zane","Asia":null,"Europe":null}
]

Explanation

Sorted columns are America=[Aria, Mateo, Zane], Asia=[Aiko, Hana], Europe=[Bruno]. Rows are aligned by position across these sorted lists.

Example 3

Input

Student:
| name  | continent |
|-------|-----------|
| Noor  | America   |
| Noor  | America   |
| Ema   | Europe    |
| Ken   | Asia      |

Output

[
  {"America":"Noor","Asia":"Ken","Europe":"Ema"},
  {"America":"Noor","Asia":null,"Europe":null}
]

Explanation

Duplicate rows are valid and must be preserved. The two America entries appear on consecutive output rows.

Constraints

1 <= number of rows in Student <= 10,000
1 <= length of name <= 100
continent is one of: America, Asia, Europe
Duplicate rows may appear in Student
For this problem version: count(America) >= count(Asia) and count(America) >= count(Europe)
Use SQLite 3.27.2 semantics for SQL submissions
For Pandas submissions, return columns: America, Asia, Europe

Student: | name | continent | |---------|-----------| | Bruno | Europe | | Aiko | Asia | | Aria | America | | Mateo | America | | Zane | America | | Hana | Asia |